I don't know of any.
It seems to me that MInputPart (at least for now) has very limited functionality. All it manages to achieve, is to confuse users and make them think that MPart, MInputPart are the new ViewPart, EditorPart.

One idea is to give up MInputPart in your application and just use MPart. It can be saved and have dirtyable property just as MInputPart. Instead of MInputPart::getInputUri():String you can use persisted state
(MPart::getPersistedState() returns a map).

We're in the process of deprecating MInputPart so using MPart is the correct approach. We're looking into providing an MEditorDescriptor in Luna to cover off the logic required to map inputs onto the correct editor implementation.